* {
    margin: 0;
    padding: 0;
    font-family: "montserrat" ,sans-serif;
    box-sizing: border-box;
}
body {
    background-image: linear-gradient(120deg,#21e7b5,#f09b3b);
    min-height: 100vh;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 10px;
}

.txtb{
    width: 100%;
border: none;
border-bottom: 2px solid #000000;
background: none;
padding: 10px;
outline: none;
font-size: 18px;
}

h3{
    margin: 10px 0;
}
.task{
    width: 100%;
    background: rgba(255,255,255,0.5);
    padding: 18px;
    margin: 6px 0;
    overflow: hidden;
}
.task i{
   float: right;
    margin-left: 20px;
    cursor: pointer;
}
.comp .task{
background: rgba(0,0,0,0.5);
color: #ffffff;
}